Triatomic molecule, linear

Herzberg (4 ) then describes the actual discovery of the CSq radical, which was produced by the flash jiiotolysis of diazomethane. The absorption band, which appeared at l4l5 a shifted when CD N rather than CI Ns was jAiotolyzed. In subsequent experiments the photolysis of confirmed the 

Very recently Katayama, Huffman, and O Bryan (47) have studied the absorption and photo ionization spectra of several isotopic water molecules in the vacuum ultraviolet. As part of this Investigation th used the spectra of lfe 0 and ife O to establish that the first electronic excited state of 1 0+ is linear. 

ACS Symposium Series American Chemical Society Washington, DC, 1975. 

In recent years Nakamoto (W) has pioneered in the use of Isotopes of the transition metals in order to make assignments of the vibrational bands of their complexes. ISy studying the spectra of °Cr(acac)s and Cr(acac)3, Nakamoto, Udovlch, and Takemoto ( ) were able to assign a band at h60 cm to a Cr-0 stretching mode and one at 592 cm to an out-of-plane ring mode. On the basis of 0 - isotopic substitution, the 592 

For tetrahedral XY4 species the totally symmetric Ai stretching mode involves no motion of the central atom, and hence should yield virtually no isotope shift when that atom is substituted. The trlply-degenerate F2 mode, however, should display an isotope effect. Thus Takemoto and Nakamoto (51) were able to assign bands in the Raman spectra of Zn(NI%)4 at T O cm and 1 10 cm to the Ai and F2 modes respectively. In this instance the isotopes Zn and Zn were used. The ordering of these two levels in this complex is somewhat unexpected, since in the vast majority of the XH4, tetrahalogeno, or XO4 species which have been examined the F2 band occurs at the higher frequency (52). 

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The situation in singlet A electronic states of triatomic molecules with linear equilibrium geometry is presented in Figme 2. This vibronic structure can be interpreted in a completely analogous way as above for n species. Note that in A electronic states there is a single unique level for K =, but for each other K 0 series there are two levels with a unique character. 

Figure 3. Low-energy vibronic spectrum in a. 11 electronic state of a linear triatomic molecule, computed for various values of the Renner parameter e and spin-orbit constant Aso (in cm ). The spectrum shown in the center of figure (e = —0.17, A o = —37cm ) corresponds to the A TT state of NCN [28,29]. The zero on the energy scale represents the minimum of the potential energy surface. Solid lines A = 0 vibronic levels dashed lines K = levels dash-dotted lines K = 1 levels dotted lines = 3 levels. Spin-vibronic levels are denoted by the value of the corresponding quantum number P P = Af - - E note that E is in this case spin quantum number),...

Figure 5, Low-eriergy vibronic spectrum in a electronic state of a linear triatomic molecule. The parameter c determines the magnitude of splitting of adiabatic bending potential curves, is the spin-orbit coupling constant, which is assumed to be positive. The zero on the...

In his classical paper, Renner [7] first explained the physical background of the vibronic coupling in triatomic molecules. He concluded that the splitting of the bending potential curves at small distortions of linearity has to depend on p, being thus mostly pronounced in H electronic state. Renner developed the system of two coupled Schrbdinger equations and solved it for H states in the harmonic approximation by means of the perturbation theory. 

The expressions for the rotational energy levels (i.e., also involving the end-over-end rotations, not considered in the previous works) of linear triatomic molecules in doublet and triplet II electronic states that take into account a spin orbit interaction and a vibronic coupling were derived in two milestone studies by Hougen [72,32]. In them, the isomorfic Hamiltonian was inboduced, which has later been widely used in treating linear molecules (see, e.g., [55]). 

By contrast to the plethora of simple oxo-halides and thiohalides of P, the corresponding derivatives of P are fugitive species that require matrix isolation techniques for preparation and characterization ClPO, BrPO, FPS and BrPS all form non-linear triatomic molecules, as expected. The corresponding oxosulfide, BrP(0)S, and its thio-analogue, FP(S)S, have also recently been isolated. 

Linear molecule A triatomic molecule in which the bond angle is 180° examples include BeF2 and C02,176 Linear polyethylene, 612 Liquid scintillation counter, 518 Liquid-vapor equilibrium, 253-254q boiling point, 230-231 critical pressure, 231-232 critical temperature, 231-232 symbol, 227... 

II electronic states, 638-640 vibronic coupling, 628-631 triatomic molecules, 594-598 Hamiltonian equations, 612-615 pragmatic models, 620-621 Kramers doublets, geometric phase theory linear Jahn-Teller effect, 20-22 spin-orbit coupling, 20-22 Kramers-Kronig reciprocity, wave function analycity, 201 -205 Kramers theorem ... 

Jahn-Teller effect, 18-20 Linear triatomic molecules, Renner-Teller effect ... 

In C02, the C=0 bond length is 116 pm, which is slightly shorter than the usual length of C=0 bonds, which are approximately 120 pm. Note that C02, N02+, SCN-, OCN-, and N20 are all triatomic molecules having 16 electrons and all are linear. 

The oxides of nitrogen that have been well characterized are described in Table 14.4. Nitrous oxide (m.p. -91 °C, b.p. -88 °C) is a 16-electron triatomic molecule having a linear structure. Three resonance structures can be drawn for this molecule as follows ... 

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